Television broadcast systems are systems responsible for the transmission of television (TV) video and audio content over the air to consumers of the content. These television broadcast systems were allocated dedicated slices or bands of frequencies, which may be referred to as “TV channels,” in both the ultra high frequency (UHF) and very high frequency (VHF) frequency bands. With the emergence of competing wire-based forms of television content distribution, such as cable television distribution systems, terrestrial forms of television content distribution, such as satellite television content distribution systems, and network forms of television content distribution systems, including Internet protocol television (IPTV) distribution systems, over-the-air television broadcast systems have become less prevalent in the delivery of television content. Consequently, the dedicated TV channels in the UHF and VHF spectrums are no longer utilized to their fullest capacity by the television broadcast systems. Historically, wireless microphones have been licensed to operate in these unused TV channels. These wireless microphones are commonly used for news gathering and in-studio applications.
Recently, these dedicated TV channels in the UHF and VHF band have been opened up for use by other devices subject to a number of requirements for operation to protect use of these frequencies by TV broadcast systems and wireless microphone systems. These new devices are referred to as either TV Band Devices (TVBD) or TV White Space Devices, as these unused TV channels are often referred to generally as “white space.” One such requirement is that these TV white space devices must first ensure the TV channel in which they will transmit is not currently in use by a television broadcast system or a wireless microphone. As a result of this requirement, these other devices are required to sense the radio frequency (RF) spectrum, dynamically identify unused spectral segments and then operate in these white spaces without causing harmful interference to television broadcast systems or wireless microphones. Considering that these demands require a certain amount of intelligence in the form of awareness of their RF environment and decision making, these TV white space devices are often referred to as “cognitive radios.”